Fig. 6. Examples of stacking with the local structure model 1.Figure optionsDownload full-size imageDownload as PowerPoint slide
Positions of atomic sites around Ba/Eu1 in the average structure SCH 727965 shown in Fig. 7. The interatomic distances between Ba/Eu1 and N1, N2, and N3 sites with the full occupation of N atoms are in the range from 2.94(3) to 3.07(3) Å. Two N4 sites and one N6 site or two N5 sites and one N7 site with the distances ranging from 3.44(5) to 3.62(5) Å are selected by the orientation of [(Al/Si)N4] tetrahedra in the dreier-ring layer. The positions of N8 and N9, N10 and N11, N12 and N13, and N14 and N15 are close to each other, having distances between Ba/Eu1 and N sites ranging from 3.07(6) to 3.37(6) Å. The Ba/Eu atom is surrounded by thirteen N atoms in the local structures. The coordination environment of the Ba/Eu atoms with N atoms does not seem to be so different in spite of the variations of the local structures by the stacking faults.